Tool



Feb. 10, 1970 v J. K. RAPP TOOL Filed Dec. 4. 1967 3 Sheets-Sheet l P P m m. K mu IH O J Feb. 10, 1970 I J.- K..RAPP[ 1 3,494,171

Toon v Filed Dec. 4. 1967 3 Sheets-Sheet 2 Marne 3.6

J. k. RAPP TOQL Feb. 10, 1970 I s Sheets-Sheet 3 Filed Dec. 4, 1967 v Fig.9

United States Patent 3,494,171 TUGL John Kristian Rapp, Chicago, Ill., assignor, by mesne assignments, to United-Carr incorporated, Boston, Mass,

a corporation of Delaware Filed Dec. 4, 1967, Ser. No. 687,634 Int. Cl. BZlf 15/00 US. Cl. 72-404 6 Claims ABSTRACT OF THE DISCLOSURE A tool for crimping contacts in which a pair of spaced locking tabs may be crimped to grip portions of a conductor, said contact element being crimped between spaced die carriers, one of which is moveable towards the other, one of said die carriers having a yieldable spring positioned to hold the contact between spaced locking members so that the contact will not be misaligned in the crimping tool during crimping. The crimping tool includes automatic siop plate means which lowers into functional position upon initial actuation of one of the die carriers so that the end of the exposed wire of the conductor may butt against the stop plate to limit the insertion of the conductor in a predetermined manner. The crimping tool is adjustable so that one of the die carriers may accommodate the tool both to conductors having varying insulation covers and to conductors with varying wire diam eters.

BACKGROUND OF INVENTION This invention relates to a tool for crimping contacts having a plurality of spaced locking elements and adapted to grip the conductor in different places.

In many electrical circuit uses type of contact is employed which is mounted on the end of an electrical conductor, the contact gripping both the insulation and the exposed wire of the conductor. Such a contact has one pair of locking members wrapped around the insulation cover and another pair of locking members to lock or grip the exposed wire of the conductor. Among such common contacts is one which has an interlocking serpent member at the other end adapted to receive another element in sliding and interlocking contact relationship. These erpent contacts are provided in various sizes.

Such contacts present problems of crimping because the locking members must grip both the insulation cover and the exposed wire. It is required that this contact be crimped accurately especially for use in sophisticated electronic circuitry.

In general, adjustment problems are encountered in this art with leads of varying insulation thickness and when wires of different sizes are used. Additional problems are encountered with respect to the degree to which the exposed end of the conductor is moved along the longitudinal axis of the contact element. In other words, the conductor should be positioned properly to a preselected axial extent to assure adequate grip ing by the locking members with no interference with the interlocking portion of the contact. Other problems are encountered relative to maintaining the correct position of the contact during the crimping operation. It is not desirable to permit the contact to rotate about its longitudinal axis since this presents the likelihood that the locking members will not be eifectively crimped onto the conductor.

The present invention is directed to the provision of an improved tool for securing contacts to leads by crimping them to the leads. An important aspect of the invention resides in the provision of automatic stop and gripping means for the leads when they are inserted into the tool.

3,494,171 Patented Feb. 10, 1970 By this means the leads are accurately positioned with respect to the contact elements and they are firmly gripped to proper orientation with respect to the contact elements. The result is that positive securing of the contact to the lead is realized with every operation of the tool and there is little likelihood that the lead will become dislodged or disoriented during the crimping operation.

In accordance with the present invention it is a primary object to provide a crimping tool which will crimp spaced locking members of the contact in an improved and efiicient manner.

Another object of the present invention resides in the provision of a crimping tool which will resist any tendency of the contact and the pre-crimped wire to rotate during the crimping operation to thereby prevent the occurrence of improper crimping of the locking members onto the conductor.

An additional object of the present invention is in the provision of a crimping tool having a stop member which moves into functional position to limit the insertion of the conductor along the longitudinal axis of the contact to a predetermined degree.

Still another object of the present invention resides in a crimping tool adapted to cooperate with means on a contact so that the contact is correctly positioned within the crimping tool.

A further object of the present invention resides in a crimping tool having easily adjustable features which permit the crimping members to be adjusted to conductors with varying insulation covers.

Another object of the present invention resides in the provision of a crimping tool adapted to cooperate with means on a contact so that the contact is correctly positioned within the crimping tool.

A still further object of the present invention resides in the provision of a crimping tool which may be hand operated while still obtaining advantages of correct positioning of the contact in the tool; resistance to rotation of the contact element during the crimping operation; automatic movement of stop means into functional position to limit the insertion of the conductor into the contact; and adjustability of the die carriers to adapt to conductors of varying insulation and wire sizes.

The invention is specifically set forth in the claims appended hereto. Further objects and advantages hereof will better be understood by a reading of the disclosure in conjunction with the drawings, in which:

FIGURE 1 is a perspective view of a hand crimping tool according to the present invention;

FIGURE 2 is a top plan view, on an enlarged scale, of a serpent contact, for example, having spaced pairs of locking members;

FIGURE 2A is a side elevational view of the contact of FIGURE 2 in position to receive a conductor with exposed wire;

FIGURE 2B is a top plan view similar to FIGURE 2 except that the interlocking members have been crimped into locking relationship;

FIGURE 3 is a side elevational view of the crimping tool of FIGURE 1, on an enlarged scale, showing details of the handle means to actuate the crimping operation;

FIGURE 3A is a front view with parts removed and parts in section, of the handle actuating mechanism of the crimping tool;

FIGURE 4 is a side view partly in section along different planes, and on an enlarged scale of a crimping assembly;

FIGURE 5 is a view along line 55 of FIGURE 4;

FIGURE 6 is a view similar to FIGURE 5 but showing the parts in a moved position;

FIGURE 7 is a front elevational view, on an enlarged scale, of the crimping operation assembly;

3 7 FIGURE 8 is a side view along line 88 of FIGURE and FIGURE 9 is a front elevational view, with parts removed, of a crimping member used in the crimping operation assembly.

The use of the same numerals in the various views will include a reference to the same structures and parts.

The crimping tool of the present invention which embodies this invention is set forth in FIGURE 1 and includes a body section 10 having a window section, indicated at 12, wherein the crimping operation assembly means is disposed. The body section 10 has a yolk 14 in which a pivotally positioned handle 16 is disposed. An elongated channel member 18 is mounted to the body section 10 by screws such as 20, 22. The screw 22 secures a retaining plate 24 which may also be secured to the body section 10 by a screw 26. A similar retaining, or cover, plate may be mounted on the reverse side of the body section, a portion whereof being shown at 22a. The elongated channel 18 operates as a handle grip and this handle grip is shown with a covering 28, which may be plastic, to facilitate gripping. The handle 16 is provided with a similar cover 28a.

In the embodiment of the invention shown in FIG- URE 1 the channel or handle 18 is stationary and fixed to body section 10 and the handle 16 is pivotally operatively associated with the handle 18. As shown in FIG- URE 3, the handle 16 is moveable from a nonfunctional position indicated by the solid line, to a functional position shown by the dashed line 30. The handle 16 is provided with a curvilinear arm 32 to which a ratchet is pivotally connected by line 34 at 36. A similar link is provided on the reverse side in this embodiment. The links are pivoted also on pin 38 which extends to both sides of the body section 10. A fixed ratchet element 40 is held in the yoke area 14 and is mounted on the pin 38. A pawl 42, pivoted at 44, is normally biased for movement in a counter-clockwise direction (FIGURE 3) by the spring 46 which is anchored to the handle 16 at 46a and to a depending ear 46b of the pawl.

The tip of the arm 32 is pivoted in a yoke portion 49 at the bottom of a ram 50 by a pin, or the like, 52 passing through the spaced portions of the yoke. When the handle 16 is pivotally moved into the direction indicated by the arrow 48, the ratchet and pawl arrangement locks the handle at different intermediate positions between the complete functional position and complete non-functional position, as defined herein.

The handle is moved against the leaf spring 52 which is anchored by a screw 53a and which urges the handle towards complete non-functional position. When the handle 16 is actuated towards functional position, the arcuate movement of the curvilinear arm 32 imparts longitudinal movement to the ram 50. The link 34 then will move about its pivot to position 34a, shown in phantom (FIGURE 3). The ram 50 communicates with window section 12 and yolk section 14. The movement of the ram 50 in the direction of handle 16 is limited by a flange or disc 56 abutting the lower ledge 58 of the window section 12.

The ram 50 moves a lower die carrier or anvil member 60 into crimping opration or engagement with upper die carrier or crimping member 62 during movement of the ram as noted hereinabove. The crimping assembly specifically illustrated is a dual assembly having one set of lower and upper die carriers 60 and 62, respectively, which can be provided to accommodate a given plastic insulated conductor; and another set 60a and 62a which can be provided to accommodate coaxial conductors. The succeeding portions of the specification will particularly describe the structures and parts associated with die carriers 60 and 62, but it can readily be seen that such a description will likewise apply to the other die carriers in the assembly.

The lower die carrier or anvil member 60 has an insulation anvil portion 68, a wire anvil portion 70 and a contact anvil holder 72. The anvil surfaces 68a, 70a, and 72a are adapted to seat the contact element shown in FIGURES 2-21).

The contact element comprises an elongated body 74 which has offset ears 76 and 7611 at one end. These ears or locking members are spaced from a pair of arcuate or curved tabs 78 and 78a on the body 74, this wall being shown with a cut out 80a which merges with cut out 80b in body 74. At the forward end of upright wall 80 is a positioning tab 82 disposed at right angles to the wall 80. The positioning tab controls the position of the contact along the longitudinal axis of the anvil surfaces (described below). An interlocking element 84 is disposed at the other end of the contact. A tab member 86 extends below the body 74, which tab may be used to facilitate the positioning of the contact in a particular circuit.

As seen in FIGURE 2b, offset ears 76 and 76a are adapted to be crimped so they grip or look the insulation cover 88 of a mating conductor. As shown, the ears are in overlapped locking relationship when crimped. The arcuate tabs 78 and 78a are adapted to be crimped in edge-to-edge relationship to lock the exposed wire 90 of the conductor.

Set screws, or the like, 92 and 94 are provided on opposite sides of the tool to hold the various anvil members in secure aligned position. These screws are adapted to engage a common threaded passageway 95. The plurality of anvil members are raised together as a lower carrier unit 60 by operation of the ram 50. The lower die carriers move in incremental steps towards the upper die carrier 62 to effect the crimping operation.

The upper die carrier includes an insulation crimper 98 and a wire crimper 100. The insulation crimper is adjustably secured to the wire crimper by a screw 102 which is adapted to pass through enlarged bore 104 and threadably engage the bore 106 in the wire crimper The enlarged bore 104 permits the insulation crimper to be adjusted to lowered or raised positions by loosening screw 102 and actuating knurled set screw 108 which is vertically translatable by threadable engagement to bore 110 of body section 10.

The wire crimper 100 has a fitted extension 112 disposed in the bore 114 in body section 10. A depression or well 116 in the extension is adapted to be engaged by a screw (not shown) disposed in bore 118. The wire crimping operation is adjustable in the sense that another wire crimper means 100 may be substituted in the window section of the body 10.

The outer insulation crimper has a crimping surface 98a and the inner crimper 100 has a wire crimping surface 100a. Wire crimper surface 98a presents a continuous curvilinear conformation to permit the offset ears 76, 76a to be locked in overlapping relationship during the crimping operation. The crimping surface 100a has a scalloped configuration so that the curvilinear tabs 78, 78a may be turned down in edge-to-edge relationship when they lock the exposed wire of the conductor.

The crimping surfaces 98a and 100a form a crimping pocket 122 in which the actual crimping of the locking ears and the locking tabs occurs. A hold-down beam spring 124 extends laterally through this pocket. One end of the spring is anchored on a shoulder 126 in Wire crimper 100. The other end of the beam spring has several turns indicated generally at 128 around the screw 102, and has a terminating stub portion 130 extending at right angles to the plane in which the turns 128 are disposed. The stub portion 130 is anchored in a socket 132 in the wire crimper 100. The straight portion of the hold-down spring lies in a plane which is parallel to the top ledge (FIG- URE 8) and bottom ledge of the window section. The spring 124 therefore is positioned between the outer insulation crimper 98 and the inner wire crimper 100 and is biased downwardly toward the anvil surfaces of the lower die carrier. The straight portion of the spring is adapted to intercept the portion of the body 74 in the gap or space between the offset locking ears 76, 76a and the curved tabs 78 and 78a. The purpose of this spring is to hold the pre-crimped wire into the crimped pocket, during the crimping operation. In standard tools the wire is placed into the pocket and then the die movement takes place to realize the crimping action. During this movement the Wire, especially stranded wire, can drop out of the pocket or move away from the nested position within the connector element. The result is that the wire may not be caught within the contact element or, at best, a poor crimp may be realized with some severed wire strands in the lead.

The apparatus of the present invention is adapted to firmly hold the wire firmly in position with respect to the contact at all times during the crimping operation. The tool first makes contact with the wire to assure a good gripping action on the wire and then it performs the crimp, as desired.

The contact element is inserted into the crimping tool by advancing the contact element along the anvil surfaces 68a, 70a and 72a until such advance is arrested by the position tab 82 on the contact element abutting against a contact locator bar 79 which is positioned behind the wire anvil surface 70a. The bar 79 is spaced laterally of the anvil surfaces and is close enough to intercept the positioning tab 82 but not close enough to interfere with other parts of the contact element.

After the contact element has been positioned on the anvil surfaces of the lower die carrier, the conductor is inserted between the paired locking members of the contact. The conductor, with the stripped wire end, is advanced to a predetermined degree because the tip of the exposed conductor abuts against an automatic wire stop member, shown generally at 136. This member has a generally square C shape and includes a top wall 138, a bottom wall 140 and a connecting back wall 142 which is normal to the top and bottom walls. The front of the top wall has depending flange members 144 and 144a which serve as the actual stops for the tip of the exposed wire.

The depending flanges are aligned with their respective anvil surfaces. The back wall 142 is adapted to slide in a track 145 which is in the back of the contact anvil and holder 72. The opposite sides of the back wall 142 have cutouts or slots 148 and 150. Screws or lugs 152 and 154 are fixed to the back of the contact anvil 72, and project outwardly of the back wall 142. The lugs intercept the bottoms of the slots to limit the movement of the wire stop in an upward direction; and the tops of the slots are intercepted by the lugs to limit the movement of the wire stop in a downward direction.

The bottom of the contact anvil 72 has a socket 158 in which the spring 160 is positioned. The end of the spring 160 which extends out of the socket bears against the bottom wall 140 of the wire stop and therefore provides a downwardly biased force on the wire stop. When the ram 50 raises the lower die carrier 60, there will be a lost motion until lugs 152, 154 move up to intercept the tops of the slots 148, 150. The lugs at the top of the slots will lift the wire stop from the lower ledge 158 of the window section whereupon spring 160 will urge the wire stop downwardly so that depending flanges 144 and 144a are likewise lowered to a position behind the curved tab portions 78 and 78a of the contact element.

The crimping tool is used by first placing the contact element on the mating anvil surfaces and advancing the contact until the positioning tab 82 abuts against the contact locator bar 79. The handle 16 then is moved to a first preliminary position which is indicated by a pawl click of the ratchet and pawl arrangement. In this position, the spring 160 has lowered the wire stop so that the flange 144 is moved to a functional position behind the locking members of the contact. This position is illustrated in FIGURE 6 of the drawings. This first incremental position of the lower die carrier allows the insertion of the lead, or conductor, which is advanced along the longitudinal axis of the anvil surfaces until the tip of the lead abuts against the flange. The handle 16 then is moved towards the functional or closed position whereupon the lower die carrier is incrementally raised by the ram. Different functions occur while executing the plurality of incrementally raised positions. The hold down wire 124 engages the contact in the gap between the spaced pairs of locking members to resist rotation of the contact and then the lower die carrier moves the contact through the crimping pocket and against the crimping surfaces 98a and 100a. Continued movement of the handle 16 allows the pawl 42 to escape the last detent of the ratchet 36 whereupon spring 50 urges the handle back to the completely non-functional position. The return to this position by the handle 16 lowers the ram 52 which is pivotally connected at the bottom to the curved portion 32 of the handle. The lowering of the ram pulls the lower die carrier down until the collar 56 and the bottom wall of the Wire stop become seated on the lower ledge of the window section 58. This completely non-functional position, or open handle position results in compressing or loading the spring between the lower die carrier and the bottom wall. The spring 160 thus is loaded for the next operating cycle when the handle and the lower die carrier will next be moved to the different positions.

The invention may now be practiced in the various ways which will occur to practitioners, and all such practice is intended to be a part of the present invention provided it comes within the terms of the following claims as given further meaning by the language of the preceding specification.

I claim:

1. A tool for crimping a contact on to a conductor in which the contact has a first pair of tabs which grip the insulation of the conductor and a second pair of tabs which grip the exposed wire of the conductors, said tool including:

a crimping die carrier,

a crimping pocket disposed in said crimping die,

a first crimping die surface in said pocket adapted to crimp a spaced pair of tabs to grip the insulation of the conductor,

a second crimping die surface in said pocket adapted to crimp the spaced tabs to grip the exposed wire of the conductor,

a yieldable hold down element traversing said crimping pocket between said first and second crimping die surfaces,

an anvil die carrier having anvil surfaces disposed opposite the two crimping surfaces, and

said tool is hand operated and said anvil carrier is moveable towards the crimping die carrier which is stationary,

a moveable handle on the tool,

means actuated by said handle to move said anvil carrier towards said crimping carrier,

ratchet and pawl means associated with said handle so that said anvil die carrier is moved by incremental steps towards said crimping die carrier,

biasing means to urge said handle towards a normally open or non-functional position wherein said anvil die carrier is lowered to a non-functional position relative to said crimping die carrier, and

said yieldable hold down element engages the contact between the spaced pair of tabs to maintain the position of the contact during the crimping operation.

2. A tool as in claim 1 which further includes:

a stop plate member positioned in said crimping pocket,

means to move said stop plate behind the spaced tab members, which are adapted to grip the exposed wire of the conductor, following a preliminary relative movement of the anvil and crimping die carriers toward each other,

said stop plate member includes a depending member positioned in the crimping pocket and said depend-'" ing member being adapted to be lowered into functional position to intercept the end of an inserted exposed Wire of a conductor to limit the travel of said conductor along the longitudinal axes of said crimping pocket,

said depending member is aligned above the anvil surfaces and said stop plate member includes a top. wall at a right angle extending to the depending member, bottom wall, and a connecting wall extending in parallel relation to a plane in which the depending member lies, and

means biasing said bottom wall away from the bottom of the anvil die carrier so that the depending member is lowered into functional position when the anvil die carrier is raised towards the stationary crimping member.

3. A tool as in claim 2 in which the elongated yieldable hold-down element is a wire spring laterally traversing a space defining the crimping pocket, one end of said wire spring being mounted in coiled relation to the face of the crimping die carrier and the other end of the coiled spring being anchored to resist displacement in a direction common to the path of travel followed by the moveable anvil die carrier.

4. A tool as in claim 2 in which the means to move the anvil die carrier is a ram having one end fixed to the bottom of the anvil die carrier and the other end pivotally connected to a curvilinear portion of the moveable handle so that movement of the handle towards a functional position raises the ram and the anvil member fixed to one end thereof into crimping operation.

5. A tool as in claim 1 wherein means to incrementally raise the anvil die carrier in crimping steps includes a ratchet and pawl associated with said moveable handle which permits the handle to be fixed in a plurality of positions between the completely non-functional position and the completely functional position of the moveable handle, and

said ratchet and pawl means being releasable following movement past the completely functional position so the biasing means urge the handle to return to a completely non-functional position.

6. A tool for crimping a contact onto a conductor in which the contact has a first pair of tabs which grip the insulation of the conductor and a second pair of tabs which grip the exposed wire of the conductors, said tool including:

a crimping die carrier,

a crimping pocket disposed in said crimping die,

a first crimping die surface in said pocket adapted to crimp a spaced pair of tabs to grip the insulation of the conductor,

a second crimping die surface in said pocket adapted to crimp the spaced tabs to grip the exposed wire of the conductor,

a yieldable hold down element traversing said crimping pocket between said first and second crimping die surfaces,

an anvil die carrier having anvil surfaces disposed opposite the two said crimping surfaces,

means to impart relative movement to one of the crimping and anvil die carriers so that an inserted contact is crimped between the crimper and the anvil when they are closed, whereby the yieldable hold down element engages the contact between the spaced pair of tabs to maintain the position of the contact during the crimping operation,

a body section,

a window in said body section,

a longitudinal bore in said body section communicating with said window at one end and extending to the other end of the body section at the other end,

, v I 8 a movable handle pivotably section,

a translatably positioned ram Within said logitudinal bore, the lower end of said ram adapted to be actuated by said moveable handle and the other end of the ram extending to t h e window section,

means to urge said moYeabIeQhandle towards a completely inactive or non-functional position whereupon said ramis not actuated,;

ratchet and pawl means'iassociatedwith said moveable handle to fix the position of said handle in a plurality of incremental positions between said completely non-functional and said completely functional positions,

the die carrier anvil fixed to the upper end of the ram extending intothe' window section, said anvil surfaces adapted to support a contact element, said contact element having an elongated body, a serpentine contact at one'end of the body, spaced ears at the other end of the body adapted to grip insulation of the conductor, and an intermediate pair of curved tabs adapted to grip the exposed wire of the conductor, the crimping pocket in said crimping die carrier positioned above said anvil supporting surface, said crimping pocket having an outer crimping surface adapted to engage the spaced ears and to crimp them around the insulation in a crimping operation, said crimping pocket having an inner crimping surface adapted to crimp the curved tabs around the exposed wire of the conductor in crimping operation,

the yieldable hold down element being a wire spring traversing said crimping pocket and lying in a plane substantially parallel to the bottom and top of said window section,

said automatic stop plate having its top wall extending into the crimping pocket in a plane substantially parallel to the bottom and top of said window section, the automatic stop plate being slidable relative to said anvil die carrier, said automatic plate having its top wall extending into the crimping pocket in a plane substantially parallel to the plane in which lies the yieldable wire element, the depending member being at the end of the top wall and lying in a plane substantially parallel to the front and back of the body section, the bottom wall extending into the window section and lying in a plane substantially parallel to the plane of the top wall, the back wall adapted to slide in a track disposed at the back of the anvil die carrier,

the biasing means between the bottom of the anvil die carrier and the bottom wall urging said bottom wall away from the bottom of the anvil die carrier when said bottom wall is moved away from the bottom ledge of the window section,

a lifting member on the back of the anvil die carrier adapted to contact a portion of the back wall when the ram raises the anvil die carrier .to thereby lift the automatic stop plate member when the anvil member is raised by the ram, whereby when the moveable handle is moved to an initial position and locked therein by the ratchet and pawl, the anvil die carrier is raised and the lifting member lifts the bottom wall of the automatic'stop plate member from the bottom ledge of the window section whereupon the stop plate'biasing'means urges the automatic stop plate downward so that the depending member is lowered into functional position behind the spaced tab members of the insertedcontact element to intercept the end of theexposed wire of the conductor,

the crimping die c'ar'rier' includes an outer'die element having said outer crimping surface,

means to adjustable position said outer die element in various lower and upper positions in said window an inner die element having said inner crimping surmounted on said body 9 face, said inner die element being detachably removable from the crimping assembly so that annother inner die element may be detachably mounted to accommodate to a different size of exposed wire conductor.

References Cited UNITED STATES PATENTS 2,729,995 1/1956 Friedman et a1. 72-404 1 0 2,744,428 5/1956 Evans 72404 2,953,185 9/1960 Lazar 29203 3,075,198 1/1963 Over 29203 5 MILTON S. MEHR, Primary Examiner US. Cl. X.R. 29203 

